Valve assembly including diameter reduction structure for trocar

Abstract

A surgical access device includes a surgical sleeve defining a central longitudinal axis and having a longitudinal passageway to permit passage of a surgical object, and a diameter reduction assembly operably couplable to the surgical sleeve. The diameter reduction assembly includes a structure foundation and at least three stand-off elements mounted to the structure foundation. Each stand-off element is positioned to engage the surgical object and is independently movable relative to the remaining stand-off elements. The at least three stand-off elements are normally biased to a first position which urges the surgical object into general alignment with the central longitudinal axis, and are adapted for distal pivotal movement from the first position to a second position to facilitate passage of the surgical object, and for proximal pivotal movement from the first position to a third position to facilitate withdrawal of the surgical object.

1. A surgical access device comprising:
 a surgical sleeve defining a central longitudinal axis and having a longitudinal passageway to permit passage of a surgical object; and 
 a diameter reduction assembly operably couplable to the surgical sleeve, the diameter reduction assembly including:
 a structure foundation including a tubular wall, a first member, and a second annular member; and 
 at least three stand-off elements mounted to the structure foundation about the longitudinal axis, each stand-off element being positioned to engage the surgical object during insertion and being independently movable relative to the remaining stand-off elements to permit passage of the surgical object, the at least three stand-off elements dimensioned and arranged to contact the surgical object and to minimize off-axis and/or angular movement of the surgical object, 
 
 the at least three stand-off elements being normally biased to a first position which urges the surgical object into general alignment with the central longitudinal axis, each of the at least three stand-off elements being adapted for distal pivotal movement from the first position to a second position distal to the first position to facilitate passage of the surgical object, and each being further adapted for proximal pivotal movement from the first position to a third position proximal to the first position to facilitate withdrawal of the surgical object, the tubular wall of the structure foundation being adapted for longitudinal movement relative to the first member and the second annular member to increase an effective length of the structure foundation to accommodate the proximal pivotal movement of the at least three stand-off elements to the third position. 
 
     
     
       2. The surgical access device of  claim 1 , including a seal proximal of the at least three stand-off elements for establishing a substantial sealing relation with the surgical object. 
     
     
       3. The surgical access device of  claim 1 , including a seal distal of the at least three stand-off elements for establishing a substantial sealing relation with the surgical object. 
     
     
       4. The surgical access device of  claim 1 , wherein the diameter reduction assembly includes a fourth stand-off element, the four stand-off elements being radially spaced about the central longitudinal axis. 
     
     
       5. The surgical access device of  claim 1 , including a seal assembly having a seal housing and a seal for establishing a substantial sealing relation with the surgical object, the seal assembly configured to be detachably mountable to the surgical sleeve. 
     
     
       6. The surgical access device of  claim 5  wherein the diameter reduction assembly is adapted for releasable mounting to the seal housing of the seal assembly. 
     
     
       7. The surgical access device of  claim 1 , wherein each stand-off element includes:
 a base configured for mounting within the diameter reduction structure foundation; 
 a head adapted to form an interrupted annular structure with the heads of the other stand-off elements, the head being configured for controlling forces resulting from parallel off-axis and angular movements of a surgical object positioned therein in a plane generally orthogonal to the central longitudinal axis; and 
 an arm connecting the base with the head. 
 
     
     
       8. The surgical access device of  claim 7 , wherein the interrupted annular structure is resistant to movement by forces in planes at angles of about 15° from an angle orthogonal to the central longitudinal axis. 
     
     
       9. The surgical access device of  claim 7 , wherein the head of each stand-off element is bulbous for controlling movement of the surgical object. 
     
     
       10. The surgical access device of  claim 7 , wherein when the at least three stand-off elements are each biased to the first position, an axis of the head of each stand-off element is displaced at an angle intersecting the central longitudinal axis.